A119993 a(n) = n-th prime from among those primes which are coprime to n.

2, 5, 7, 11, 13, 19, 19, 23, 29, 37, 37, 43, 43, 53, 59, 59, 61, 71, 71, 79, 83, 89, 89, 101, 101, 107, 107, 113, 113, 137, 131, 137, 149, 151, 157, 163, 163, 173, 179, 181, 181, 197, 193, 199, 211, 223, 223, 229, 229, 239, 241, 251, 251, 263, 269, 271, 277, 281

Offset

1,1

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Formula

a(n) = A000040(n + A001221(n)). - Jon Maiga, Jan 05 2019

Example

5,7,11,13,17,19,23,... is the sequence of primes which are coprime to 6. 19 is the 6th such prime, so a(6) = 19.

Maple

f:= n -> ithprime(n + nops(numtheory:-factorset(n)));
map(f, [$1..100]); # Robert Israel, Sep 28 2023

Mathematica

With[{prs=Prime[Range[1000]]}, Table[Select[prs, CoprimeQ[#, n]&][[n]], {n, 60}]] (* Harvey P. Dale, Aug 27 2014 *)
Table[Prime[n + PrimeNu[n]], {n, 60}] (* Jon Maiga, Jan 05 2019 *)

Prog

(PARI) {m=59; for(n=1, m, q=2; k=n; while(k>0, p=q; if(gcd(p, n)==1, k--); q=nextprime(p+1)); print1(p, ", "))} \\ Klaus Brockhaus, Aug 15 2006

Crossrefs

Cf. A000040, A001221.

Sequence in context: A265809 A303112 A182320 * A045346 A039675 A074833

Adjacent sequences: A119990 A119991 A119992 * A119994 A119995 A119996

Keyword

nonn

Author

Leroy Quet, Aug 03 2006

Extensions

More terms from Klaus Brockhaus, Aug 15 2006

Status

approved